What is a stump tournament? It could be a denim trivia contest. It could be the obscure beer-drinking game in which players attempt to drive each other’s nails into a tree stump with a hammer that is first tossed in the air for a full revolution, caught, and brought to bear on the stump, all in one fluid motion. Or, it could be something else altogether, but it starts at 6 pm. Austin artists who use their hands may be making a lot of conceptual art for the next few weeks.